Bellman_Ford

//-----------Bellman_Ford------------
struct Edge
{
    int v,u;
    int weight;
}edge[M];
int dist[N];

bool Bellman_Ford(int n,int m,int s)
{
    int i,j;
    bool flag;
    for(i=1;i<=n;i++)
        dist[i]=MAXVAL;
    dist[s]=0;

    for(i=1;i<n;i++)
    {
        flag=false;
        for(j=0;j<m;j++)
        {
            if(dist[edge[j].v]+edge[j].weight<dist[edge[j].u])
                dist[edge[j].u]=dist[edge[j].v]+edge[j].weight,flag=true;
        }
        if(flag==false)    return true;
    }///显然写的是单向的!
    for(j=0;j<m;j++)
    {
        if(dist[edge[j].v]+edge[j].weight<dist[edge[j].u])
            return false;
    }
    
    return true;
}

写的不对或不好的地方，请大虾多多指教!    ——Never